likely regex (eregi) problem -- input allows non-digit characters

[stevieontario]

Afternoon freaks,

 

I'm trying to customize a free bit of calculator code I got from the web. There's a regex in it that appears designed to prevent users from entering anything but digits in the input fields.

 

However, it does allow "garbage" in, e.g. 55f x 45e = 2475

 

How  can I redo the regex so that it only allows digits and one decimal?

 

The regex uses eregi, which the PHP manual says has been deprecated. I don't think that's the main issue though.

 

The code containing the regex is here:

if(!eregi("[0-9]", $number1)){ 
          echo("Number 1 MUST be numbers!"); 
          exit;

... and this is the entire code:

<?php 
// Calculator Script v1 
// Copyright (C) 2007 RageD 

// Define to make this all one document 
$page = $_GET['page']; 

// Defining the "calc" class 
class calc { 
     var $number1; 
     var $number2; 

          function add($number1,$number2) 
          { 
                   $result =$number1 + $number2; 
                    echo("The sum of $number1 and $number2 is $result<br><br>"); 
                    echo("$number1 + $number2 = $result"); 
                    exit; 
           } 

          function subtract($number1,$number2) 
          { 
                   $result =$number1 - $number2; 
                    echo("The difference of $number1 and $number2 is $result<br><br>"); 
                    echo("$number1 - $number2 = $result"); 
                    exit; 
           } 

          function divide($number1,$number2) 
          { 
                   $result =$number1 / $number2; 
                    echo("$number1 divided by $number2 is $result<br><br>"); 
                    echo("$number1 ÷ $number2 = $result"); 
                    exit; 
           } 

          function multiply($number1,$number2) 
          { 
                   $result =$number1 * $number2; 
                    echo("The product of $number1 and $number2 is $result<br><br>"); 
                    echo("$number1 x $number2 = $result"); 
                    exit; 
           } 
} 
$calc = new calc(); 
?> 
<TITLE>PHP Calculator v1</TITLE> 
<form name="calc" action="?page=calc" method="POST"> 
Number 1: <input type=text name=value1><br> 
Number 2: <input type=text name=value2><br> 
Operation: <input type=radio name=oper value="add">Addition <input type=radio name=oper value="subtract">Subtraction <input type=radio name=oper value="divide">Division <input type=radio name=oper value="multiply">Multiplication</input><br> 
<input type=submit value="Calculate"> 
</form> 
<?php 
if($page == "calc"){ 
$number1 = $_POST['value1']; 
$number2 = $_POST['value2']; 
$oper = $_POST['oper']; 
     if(!$number1){ 
          echo("You must enter number 1!"); 
          exit; 
     } 
     if(!$number2){ 
          echo("You must enter number 2!"); 
          exit; 
     } 
     if(!$oper){ 
          echo("You must select an operation to do with the numbers!"); 
          exit; 
     } 
     if(!eregi("[0-9]", $number1)){ 
          echo("Number 1 MUST be numbers!"); 
          exit; 
     } 
     if(!eregi("[0-9]", $number2)){ 
          echo("Number 2 MUST be numbers!"); 
          exit; 
     } 
     if($oper == "add"){ 
          $calc->add($number1,$number2); 
     } 
     if($oper == "subtract"){ 
          $calc->subtract($number1,$number2); 
     } 
     if($oper == "divide"){ 
          $calc->divide($number1,$number2); 
     } 
     if($oper == "multiply"){ 
          $calc->multiply($number1,$number2); 
     } 
} 
?>

I tried amending the regex inside the quotes to this:

[\d.]

... but no dice.

Edited May 30, 2013 by stevieontario

[requinix]

All your expression does is check the string contains a number.

 

ctype_digit

 

And avoid ereg/POSIX functions. They're old and deprecated and not as powerful as the preg/PCRE functions.

[stevieontario]

still alive, thanks. ctype looks like a promising way forward but man it looks like a lot of trial and error and testing! well, here goes...

 

thanks again.

[requinix]

Trial and error? Do you have another question besides how to check that something is a number?